1. [1 pt] The goal of the 4 -queens problem is to place 4 queens on a 4 rows 4 columns chessboard, such that no two queens attach each other. One solution to the 4-queens problem is shown in Figure 1. Design a search-based solution to solve the 4-queens problem. Your solution must include following four components: a. Define state and show examples of three states (including initial state and goal state) [0.25pt] b. Define a successor function, and estimate total number of states, based on the defined successor function [0.25pt] c. Show state graph with at least five states and their relationships (the graph must have a path from initial state to goal state) [0.25pt] d. Show how to find solution(s) from the state graph [0.25pt] 1154101